Method of crushing



April 1939- w. H. SCHACHT- 5 2,155,151

METHOD OF CRUSHING Filed March 26, 19:54 3 Sheets-Sheet 1 'l I ffiwzziarP4 ll I April w. H. SCHACHT 2,155,151

METHOD OF CRUSHING Filed March 26, 1954 3 Sheets-Sheet 2 I h a April1939- w. H. SCHACHT 2,155,151

METHOD OF CRUSHING Filed March 26, 1934 3 Sheets-Sheet 3 Patented Apr.18, 1939 UNlTED STATES PATENT OFFICE METHOD OF CRUSHING William H.Schaclit, Painesdale, Mich. Application March 26, 1934, Serial No.717,288

4 Claims.

ported and is delivered at a time when the particles are not engaged byany crushing surface other than the impact surface. I avoid any nip orcrushing action in which the particle is simultaneously gripped by twoopposed surfaces. Another purpose is the provision of a crushing methodin which the particles impacted, or the smaller particles to which theyare reduced by the impact, are directed by such impact against asecondary impacting surface, where an ensuing crushing or disintegratingimpact is received. Another purpose is the provision of a crushingmethod in which the particles to be crushed are passed by gravitythrough a crushing zone defined by the path of movement of a successionof impacting members. Other objects will appear from time to timethroughout the specification and claims.

The present application is a continuation-inpart of my application No.650,597 filed on J anu- Figure 2 is a section on the line 22 of Fig ure1;

Figure 3 is a section on the line 33 of Figure 2;

Figure 4 is a front end view with parts in section;

Figure 5 is a schematic diagram; and

Figure 6 is a vertical section of a variant form.

Like parts are indicated by like symbols throughout the specificationand drawings.

Referring to the drawings, A generally indicates any suitable fixedsupporting structure upon which may be mounted any suitable supportingmember A held in place for example by the bolts A I indicates animpeller spindle to which is secured the impeller structure generallyindicated as 2 which includes a disc B and a laterally spaced ring B thering and disc being connected by a plurality of impeller vanes or strutsB which are clearly shown in section as in Figure 3. Positioned adjacentand preferably abutting against the impeller vanes B are the impellerstriking or wearing plates B of which three are shown in Figures 3 and5, it being understood that the number may be varied. The impeller plateB may include a collar or hub B surrounding the end of the impellershaft I the parts being held against movement as by the bolt B and thenut B and the key B". Any suitable means may be employed for rotatablysupporting the impeller shaft or spindle I as for example the pedestaland hub bearing bed plate A with its pedestal supports C in which may bemounted the shaft or spindle bearing sleeve C held in place as by theclamp members C which may be tightened as by the bolts and nuts C.

Positioned within the bearing sleeve C are any.

suitable roller bearings C within the inner race of which is positionedthe shaft or spindle I. C" indicates a terminal driving pulley for theshaft or spindle which may be secured to the-end of the spindle Iwhereby the spindle and the impeller may be rotated. C indicates a mainbearing adjusting sleeve within the spindle bearing sleeve C It will beclear from the figures that whereas the member B is shown as a disc themember B is a ring laterally spaced from and opposite to the peripheryof the disc B, whereby, as will later appear, material may be fed forfree gravital fall between the disc B and ring-B to the wearing plate BSurrounding the impeller structure is the impeller housing structuregenerally indicated as D. D is the impeller housing bearing which may bemounted in any suitable way on the base A. D indicates an impellerhousing ring bearing hub. D indicates any suitable anti-friction bearingand D is the impeller housing driving sprocket. The housing includes afiat portion D which is outwardly flared as at D and terminates in aspecies of circular track D which may be supported upon trunnion rollersD rotatable upon adjustable trunnion roller frames D which may beadjusted as by the screw device D upon the trunnion roller base D". Theinterior of the impeller housing is provided with any suitable linerplates D as shown in Figure 2.

Mounted within and rotating with the impeller housing is a refiectorring E. The reflector ring may be supported for example by a pluralityof generally radial elements or braces E as will be clear from Figure 3.E indicate any suitable reflecting ring striker plates which may be heldin position as by striker plate clamps E and clamp bolts E As will beclear for example from Figure 2 the striker plates lie in the plane ofrotation of the impeller wearing plates 28 and any material which passesbetween the impeller plates or which is driven from the impeller platesby the crushing or disintegrating impact, is received by the strikingplates. As will later appear, the rate of feed and the rate of rotationis such that material cannot drop through the path of movement of thestriking plates without receiving a crushing or disintegrating impact,the action of which is indicated for example in Figures 3 and 5.

Further secured to the impeller housing struc- I ture is acircumferential grizzly-or screen generally indicated as G. It may bebolted or otherwise suitably secured to the outer edge of the impellerhousing as at G and is provided with a forward circumferential side ringG Associated with the rotating grizzly structure are a plurality ofelevator buckets G which therefore rotate unitarily with the impellerhousing. Any material which fails to pass through the grizzly or screenis picked up by the buckets and upwardly conveyed until aligned with anddischarged upon the surfaces of the oversize return chutes G The mainline of feed is along the feed chute G and the oversize chutes G returnthe oversize picked up by the buckets G to the main line of feed alongthe chute G The result is a closed crushing and screening circuit, theonly normal escape from the circuit being through the screen.

However, it may happen, as in screening copper ore, that uncrushablemasses of native copper may accumulate in the circuit. Similarly,uncrushable masses may accumulate in the crushing and screening of othermaterials. In order to permit the removal of such material I provide arejector chute generally indicated as H which may be pivoted as at H andwhich may be moved inwardly into the line of feed or delivery along thechute G whereby the feed, or oversize, may

be temporarily by-passed to the picking deck.

H, for the removal of the undesired particles. The deck H may be pivotedas at H whereby it may be dropped into the dotted line position as at H,after the picking has been completed. H indicates a picking deck returnchute, which delivers the particles on the deck back into the crushingand screening circuit.

Referring to Figure 1, I preferably employ a plurality of motors. Iillustrate for example a primary motor for the impeller, which isprovided with a pulley O slotted to receive a plurality of belts O whichserve to drive the pulley C of the impeller shaft. A secondary motor 0through any suitable gear reducer 0 may drive the sprocket O and therebythe chain 0 passing about the sprocket D of the impeller housing.

It will be realized that whereas I have described and shown a practicaland operative means for carrying on my invention or method, neverthelessit may be practiced by other and substantially different mechanisms. Forexample, whereas I have illustrated the impact members as rotating abouta horizontal axis, it will be understood that some or all might berotated about a vertical axis or axes. Whereas I have shown the impactmembers mounted upon a single rotating member, it will be understoodthat I might employ impact members mounted on one or two rotary membersrotating about the same axis. Whereas I have shown a rotary outerreflecting surface E of generally cylindrical shape, it will beunderstood that this outer reflecting surface may be of different shape,as for instance, conical, and may be segregated instead of smooth. Itmay be advantageous to move it, or it need not be moved. It will,therefore, be understood that my description and drawings are to betaken as broadly illustrative or diagrammatic rather than as limiting meto the precise mechanism shown for practicing my method.

The use and operation of my invention'are as follows:

Broadly stated my method relates to the reduction of ore, rock or othermaterial by disarsarsr integrating it by a series of impacts. In theparticular device herein shown for carrying out my method, Idisintegrate the ore or rock by a series of impacts with the striking orwearing plates B which are fixed radially, or nearly so,

to the impeller.

The impeller includes the circular disc B which is mounted centrally atthe end of the spindle i. The impeller and the impeller housingstructure generally indicated as D rotate about a common axis, but areseparately rotated and preferably at greatly different speeds. Materialmay be fed down the main feed chute G and is thereby delivered into thespace between the plate or disc B and the ring B of the impeller. Thematerial falls by gravity and preferably the chute is of sufficientlength or the height of initial feed is sufllcient to impart a verysubstantial gravity acceleration. Furthermore, the vanes of the impellerhave a fan effect which tends to discharge air radially outwardly fromthe inner space of the impeller and this air movement further speeds thefalling particles after they pass below the axis of rotation of theimpeller. Therefore the material to be reduced is fed at a high rate ofspeed through the open end of the impeller on its downward path from thefeed chute and, as it passes between the disc B and the ring B into theline of movement of the striking plates B each particle receives adisintegrating impact.

The impeller revolves at a high rate of speed about its horizontal axis,at such a rate that in order to intercept an impact of all orsubstantially all of the falling particles, one, two or three or more ofthe members B may be necessary. The feed chute G5 may be steeplyinclined, at an angle of 60 degrees more or less. The falling particlesattain suflicient velocity relative to the velocity of the impellerstriking plates B to reach the path of the impeller plates before theyare struck and the rates of-rotation and the length of fall arepreferably so timed and arranged that the particles make a full andcomplete contact with the faces of the striking plates B rather thanmerely being struck by the top edges only.

The annular ring B serves not only to support the ends of the struts buthas the secondary function of confining and directing the passage of thebroken ore or rock and also to create a definite air circulation throughthe impeller, to help carry the material or particles therethrough.

The reflector ring E with the plates E surrounds and is concentric withthe impeller, revolving about the same axis. After impact with theimpeller striking plates B the broken or partly disintegrated materialinstantlyattains a high velocity, due to centrifugal force acting on itby the rotating impeller, and is thrown outwardly from the impeller andupwardly and outwardly against thewearing plate E of the reflector ring.Centrifugal force, combined with the force of the air current set up bythe impeller, act on the material in the same general outward direction,giving it a high velocity which directs the particles against thewearing plates E resulting in a secondary reduction of the material.

There is some further reduction of particles of ore or rock caused bytheir striking each other in passing from the impeller to the reflectorring plates and vice versa. There is also some further reduction causedby particles bounding or rebounding from the reflector plates and againgetting into the path of therevolving impeller striking plates.

For screening the disintegrated product I provide a circumferentialscreen or grizzly whichrotates in unison with the impeller housing. Theparticles which are sufficiently reduced will pass through the screen orgrizzly to any suitable conveying means. The oversize particles whichcannot pass through the grizzly are picked up by the buckets G and arethereby returned to the oversize return chutes G and thus to the feedchute G.

As the result is a closed screening and disinte grating circuit, anynon-reducible material should be removed from the circuit. For removingsuch material, such as tramp iron, steel, or native copper, or the likeI may intercept the flow of the oversize return feed by the chute H,without shutting down the machine. It simply intercepts the oversizereturn and directs it to the picking table II. The uncrushable materialis there picked and removed and the residue may be returned by tiltingthe table II to deliver it to the return chute H This ready means ofremoving uncrushable material makes unnecessary the use of a magneticpulley for the removal of tramp iron or steel. Such foreign material canenter the machine without causing injury, because the clearance betweenthe impeller and reflecting ring plates is several times the opening ofother crushers making a product the same size. In other words, all thatsuch uncrushable particles will do is to travel around the closedcircuit without being disintegrated or screened. When there issufficient accumulation of such particles to make it worth while, therejector'chute H is simply moved into position and such particles willthen be delivered to the picking table H for removal by picking.

The control of the intensity of the impact forces is a matter ofimportance. For a given diameter of impeller and a given speed, theintensity with which the partly reduced material is thrown out againstthe reflector ring, wear plates or the secondary impeller strikingplates, by the impeller is controlled by the variation of the anglebetween a radial line drawn through the center of the impeller and somepoint on the plane of the face of the impeller striking plate. Theintensity may therefore be varied by merely changing the angle of thefaces of the members B opposed to the material. The intensity may alsobe controlled by varying the speed of the impeller and by varying thediameter of the impeller. The combination of these varying factors makespossible a control of the breaking force to suit the requirements forbreaking ores or rock of different hardness or size in order to get thegreatest amount of work out of a given power input.

In defining the operation of my device I may employ the term inner pathas the inner margin or inner face of the path described by the impactmembers as they run in their normal operation, the cylindrical surfacedefined by that part of the impeller members nearest their'center ofrotation. The outer path is the corresponding cylinder defined by theparts of the impellers farthest from their center of rotation. While Isay cylindrical for purpose of illustration, it will be understood thatI do not wish to be limited to any particular figure or shape, as thepath might be conical or otherwise shaped. I

Referring to the accompanying sketch, Figure 5, which is a cross sectionthrough the impeller striking members and breaker or reflector ring, Iillustrate the mode of practicing my method by means of the structureelsewhere described of rotary impellers and a rotary reflector ring. 3shows in general the position of any impeller striker face at theinstant it impacts a portion of the feed as it falls into the path ofthe impeller striker members. M shows the shattered material contactingthe impeller striker face at the instant of impact. S shows generallythe position of the impeller striker face as it begins to discharge theshattered material against the breaker and reflector ring. M shows theshattered-material on its way to the breaker ring. S" shows generallythe position of the impeller striker face when it has completed thedischarge of the shattered material to the breaker ring. M" shows theshattered material after its impact with the breaker ring with itsresultant further shattering.

The material to be crushed or shattered is gravitally directed at a highvelocity substantially into the path of the revolving impeller impacmembers from the steeply inclined chute G The initial or primarybreaking takes place at S, as the impeller striker impacts and shattersthe material on its fall through this crushing zone.

The secondary reduction takes place along the inner surface of thebreaker and reflector ring and in a space along said ring asindicated byX, which space is located substantially, in the upper half of thebreaker ring. The partly shattered material M is thrown centrifugallyagainst the ring from the impeller striking members; the

resultant impact further shatters and disintegrates this material. Whilestill contacting the breaker ring, this twice shattered material M"receives a bombardment of many crushing 11npacts from the materialthrown against it by subsequent impulses of the impeller as these aredelivered upward of thirty to fifty per second. The more finely reducedmaterial is instantly blown aside by the air current set up from theimpeller fan action, leaving only the coarser material in contact withthe breaker ring to receive the subsequent impacts from the oncomingstill coarser material M, which produces a crushing action on thematerial M" as it is caught between the breaker ring and the material M.By the prompt removal of the finer material from this crushing zone bythe air current above mentioned, reduction of v the material to extremefineness is prevented. As this latter or secondary crushing takes placein substantially the upper half of the inner circle of the breaker andreflector ring, it will be readily seen that no bedding of the materialin this crushing zone is possible. On the contrary, effective andefficient crushing results, because the material to be crushed is caughtdirectly and squarely between the two crushing surfaces, namely; thebreaker ring and the oncoming material, and is not cushioned by anybedded material.

The breaker and reflector ring, revolving slowly, constantly exposes aclean surface to the material in the area X, thus distributing the wearevenly over the entire surface of the breaker ring.

As the crushed material particles M" fall or are reflected from thebreaker and reflector ring much of it again enters the path of theimpeller striking members and receives further shattering impacts.sequently finds its way to the screen or grizzly revolving with thebreaker ring housing. The undersize material passes through the screen,and the oversize is returned by buckets, attached to the revolvinggrizzly or screen housing, which This crushed or shattered material sub-I discharge this oversize material into the feed chute on top of theincoming feed, thus returning the oversize with the new feed to thecrushing circuit.

I would call attention to the following: The position of X, that is, thesecondary crushing zone, as indicated in the sketch, was determined byactual test. This .position varies with the speed of the impeller, 'withthe angle that the striking face makes with a radial line, and with thedepth that the material penetrates into the path of the striking plates.In other words, this crushing area x can be, by the variation of any oneof these factors, brought so that it will lie wholly in the upper halfof the breaker ring, if desirable.

The particles to be crushed are dropped into the path of the impellersat a speed which is so related to the speed of the impellers that theparticles to be crushed penetrate substantially entirely into the pathof movement of the impellers or strikers before being impacted. Thespeed may vary. For example, there may be 35 impulses per second at 700R. P. M. and 47 impulses per second at 950 R. P. M. These speeds andfrequencies are merely illustrative, but are sufiicient, in practice, tocause an eflicient primary disintegration. The secondary disintegrationtakes place thereafter along the above mentioned zone X of Figure 5.Assume that the reflector ring is actually moving, say at the rate of ofan inch for each impact. As the particles centrifugally deliveredagainst the zone A rest against the surface for an appreciable time, inthe neighborhood of half a second, before they begin to fall away bygravity. Particles already positioned against the ring receive abombardment of the larger particles thrown outwardly by the impeller. Asabove mentioned, the fan action blows the fines away, preventingformation of a pad or bed which would interfere with crushing.

While I prefer to employ gravity as the means for imparting to thematerial the proper speed for carrying it into the primary crushingzone, it will be understood that I may practice my method with theemployment of other means for accelerating the particles to be crushed.I\may, for example, project a stream of particles into the crushing zoneby any suitable mechanical means, conveyors, projectors or the like.

As specific examples of variant means for practicing my method, Iillustrate, in Figure 6, a vertical rotor P having a plurality of impactmembers P and a chute P adapted to drop the material to be crushed intothe path of these impact members. P is a reflector member, also rotatingabout a vertical axis, and adapted to receive the impacts of thematerial centrifugally delivered by the impact members. P is anysuitable discharge chute.

I claim:

1. The method of multiple stage impact crushing which includes, first,projecting by gravity, and along a generally defined path, a stream ofparticles to be crushed; moving transversely through said path asuccession of primary impact members, at such speed and momentum as willcause adequate crushing impacts to the dropping particles of saidstream; maintaining the velocity of the particles fed into the primarycrushing zone formed by the intersection of the path of feed and thepath of the impact members sufficiently high, in relation to the speedand spacing of the succession of impact members, to carry substantiallyeach particle of the stream fully into the path of the impact memberwhich impacts it, whereby such particle is positioned to be squarelyimpacted by the impact face of such impact member; directing theimpacted particles outwardly, as the result of said impact, from theprimary crushing zone; terminating the outward flight of the impactedparticles by a secondary crushing impact at a secondary crushing zoneremoved from the primary crushing zone and thereafter gravitallywithdrawing the broken particles through a zone of withdrawal remotefrom the primary impact zone.

2. The method of impact crushing which includes, first, projecting bygravity, and along a generally defined path, a stream of the particlesto be crushed; moving transversely through said path a succession ofimpact members, at such speed and momentum as will cause adequatecrushing impacts to the dropping particles of said stream; maintainingthe velocity of the particles fed into the crushing zone formed by theintersection of the path of feed and the path of the impact memberssufficiently high, in relation to the speed and spacing of thesuccessive impact members, to carry substantially each particle of thestream fully into the path of the impact member which impacts it,whereby such particle is positioned to be squarely impacted by theimpact face of such impact member, and thereafter withdrawing the brokenparticles from the crushing zone.

3. A method of impact crushing which includes moving a succession ofimpact surfaces through a crushing zone, projecting downwardly inresponse to gravity an unconsolidated stream of freely fallingparticles, and directing said stream transversely through said crushingzone; proportioning the speed of said impact surfaces /and saidparticles such that the time required for a single particle to passthrough said zone is generally the same as the time interval between thepassage of successive impact surfaces through said zone, whereby topermit all of said particles to enter the spaces between successiveimpact surfaces an extent suflicient to insure a. full face primarycrushing impact; and causing said particles in response to said primaryimpact to travel laterally without obstruction entirely out of saidprimary crushing zone.

4. A method of impact crushing which includes moving a succession ofimpact surfaces through a crushing zone, projecting downwardly inresponse to gravity an unconsolidated stream of freely fallingparticles, and directing said stream transversely through said crushingzone; proportioning the speed of said impact surfaces and said particlessuch that the time required for a single particle to pass through saidzone is generally the same as the time interval between the passage ofsuccessive impact surfaces through said zone, whereby to permit all ofsaid particles to enter the spaces between successive impact surfaces anextent sufllcientto insure a full face primary crushing impact; causingsaid particles in response to said primary impact to travel laterallywithout obstruction entirely out of said primary crushing zone; andterminating the lateral flight of said particles by a secondary crushingimpact at a secondary crushing zone removed from said primary crushingzone.

W H. SCHACHT-

